Electrons are an interesting particle because the smallest particle in existence (excluding branes and strings), yet they are very common, you will find at least one in each atom, and plenty more ‘Free’ electrons in many electrical appliances.
The Atoms Electron
The atom has a nucleus and a swarm of electrons, the swarm of electrons being the most important part. Without these electrons, atoms would not couple to molecules, and molecules would not couple into particles, this is because electrons have a magnetic pull that drags them, and whatever they are attached to into a certain ‘Orbit’ around other particles.
They also have another feature caused by their magnetic pulls, they stop atoms going through each other! If no electrons existed, everything would be a mess of protons and neutrons just binding together to the critical density, and everything would collapse into a black hole.
The Static Electricity
Electrons can be stored and moved, for example, if you have fleece socks and you slide across the fluffy carpet, it will create so much electricity (a mass flow of electrons) to the point that you can power a neon bulb for a split second! This is because the friction on that high electron material will interchange the electrons into your body from the carpet, and create some on the fly as well. The electricity created will build up, and when you touch a conductive object (metal doorknob) it will all flow out, if there is enough, it will jump through the air and create photons from the excited electrons in the atoms as it passes, creating an arc, also known as mini lightning.
How Electricity Works
Electricity, if not being looked at on the subatomic scale, can be imagined as water, it will flow from high to low (in reality, the electron is a negative charge, so it will flow from negative to positive), and light bulbs can be imagined as a converter, that converts the water into light and heat.
If you hook up a battery (storage device for massive amounts of electrons) to a circuit and a light bulb, it will glow, and if you snip the wire, electrons will not flood over the table and try to zap you, don’t worry, because they will have nowhere to go, so they will flow back into the battery, although, for pranks it would be quite funny for a drip of electrons to fall on someone.
Computers work via manipulating electrons to turn switches on and off, and in some interesting ways, the digits will change data, do computations and other interesting things, not even i know exactly how a CPU works, for it is too complex for anyone to understand.
How Small Is An Electron?
To get how big an electron is, we will have to go in steps, because it is one of the smallest things in the universe. First, we will look at the size of an atom, so, imagine an earth that is hollow on the inside, then, fill the earth with oranges, already, that is a lot of oranges, then, you would shrink that earth full of oranges to the size of an orange, then, each orange inside would be the size of an atom.
Next, we will get that atom and make it the size of the earth again, then, you can hide a blueberry seed (Yes, a blueberry seed) inside that world sized atom, then shrink it to the size of an orange (wow), then fill a world sized container with those orange sized atoms, and then shrink that world to the size of an orange, each blueberry seed in each atom is the size of the nucleus, the core of protons and neutrons, that blueberry seed would have about 10 protons and 10 neutrons.
Get that nucleus and extract a proton from it, then extract the three quarks and the three gluons from that proton. Now that you have the size of a quark, shrink that quark by x10 and that will give you the size of a single electron! Now that is a small particle, in fact, it is made of a vibrating string (that is infinitely thin), and at times, an infinitely flat Brane (2d plane is a D-Brane, this is the one i am talking about).